12 ELEMENTARY FORESTRY. 



derived from a single flower. As used in nursery practice the 

 term is generally applied to seeds having a fleshy covering- or 

 an adjoining fleshy part. 



The Seed, botanically defined, is the ripened ovule, but as 

 the term is used in nursery practice it often includes the ovary 

 and other parts that may be attached to it. What is common- 

 ly called the seed of Maple, Ash, Elm, Walnut and Basswood 

 is really the fruit. 



Distribution of Seeds. The seeds of plants are distributed in 

 various ways, the most common of which are (1) by means of 

 floats or wings which buoy the seeds up in the air or water 

 and (2) by animals. The seeds of Ash, Arbor Vitae. Box 

 Elder, Catalpa, Elm, Maple, Pine and Spruce have wings 

 which allow them to be blown great distances by the wind, 

 especially when they break loose from the upper branches of 

 high trees during severe winds. The seeds of the Honey 

 Locust are not shed from the pod until after the pod has fallen 

 and as the pod is ten inches or more long and spirally twisted 

 it may be blown long distances on level ground or snow crust. 

 The seeds of the poplars and willows have a cottony float at- 

 tachment which buoys them up in the air. In the case of the 

 Basswood, the parachute-like bract attached to the seed 

 cluster aids in spreading the seeds by carrying them through 

 the air or along the snow crust. The seeds of Mountain Ash, 

 Wild Black Cherry, Hawthorn and others are largely distri- 

 buted by wild animals which eat the fruit and allow the seeds 

 to pass through the alimentary canal uninjured or carry off 

 the fruit and spit out the seeds. - Many seeds or seed vessels 

 have bur-like or sticky coats by which they adhere to animals 

 and are thus carried considerable distances. Very often 

 bodies of water aid in the distribution of seeds since all that 

 are spread by the agency of the wind and most of those that 

 have fleshy coverings will float on the surface of the water 

 and may in this way be scattered. 



Shapes of Trees. Different species of trees naturally develop 

 different shapes. Some, like Spruces, Tamarack and Balsam 

 have a decided tendency to form a strong stem and to take on 

 a conical form in preference to the development of a crown or 

 head while others like the Basswood, Oaks, Maples and Box 

 Elder develop their crown in preference to their stem. The 



